Patent US4375328A successfully refreshed from Google Patents.
US4375328A
Expired / Lapsed
US
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Electrophotographic device with light quantity control
Assignee: Canon Inc
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Filing: 1980-05-09
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Granted: 1983-03-01
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Expires: 2000-05-09
Abstract
Abstract An electrophotographic device constructed with a light irradiating device to irradiate light on a photosensitive member, a charging device to uniformly charge the photosensitive member after the light irradiation by the light irradiating device; a light image projecting device to project a light image after the charging by the charging device to thereby form an electrostatic latent image corresponding to the light image on the photosensitive member, a developing device to develop the electrostatic latent image, and a control device to vary the irradiated light quantity by the light irradiating device and the exposure light quantity by the light image projecting device in accordance with a potential state of the photosensitive member at the time of the latent image formation.
Inventors
- 👤 Hiroaki Tsuchiya
- 👤 Yasuhide Kurosaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 15:32
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/043
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
133 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiation by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) control means to vary the irradiated light quantity by said light irradiating means and the exposure light quantity by said light image projecting means with lapse of a lighting time in said light source so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said lapse of lighting time.
Claim 2
Dependent Claim
133 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiation by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) control means to vary the irradiated light quantity by said light irradiating means and the exposure light quantity by said light image projecting means with lapse of a lighting time in said light source so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said lapse of lighting time.
Claim 3
Dependent Claim
46 words
The electrophotographic device according to claim 1, wherein said control means includes time constant means, an output of which varies with lapse of said lighting time, and said irradiated light quantity and said exposure light quantity are controlled by the output from said time constant means.
Claim 4
Dependent Claim
36 words
The electrophotographic device according to claim 2, wherein said control means has a light adjusting circuit to electrically adjust said irradiated light quantity and said exposure light quantity by the output from said time constant means.
Claim 5
Dependent Claim
45 words
The electrophotographic device according to claim 2 or 17, wherein said time constant circuit further counts the stoppage time of the device, and adjusts said irradiated light quantity and said exposure light quantity in accordance with lapse of said lighting time and said stoppage time.
Claim 6
Dependent Claim
23 words
The electrophotographic device according to claim 4, wherein said time constant circuit is constructed with a charging and discharging circuit of a capacitor.
Claim 7
Dependent Claim
24 words
The electrophotographic device according to claim 5, wherein the time constant in said charging and discharging circuit differs in the charging and the discharging.
Claim 8
Dependent Claim
29 words
The electrophotographic device according to claim 6, wherein said charging and discharging circuit is charged with lapse of the lighting time and discharged with lapse of the stoppage time.
Claim 9
Dependent Claim
135 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiation by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) light quality control means to vary the irradiated light quantity of said light irradiating means and the exposure light quantity of said light image projecting means in accordance with a length of a stoppage time of said device so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said stoppage times.
Claim 10
Dependent Claim
135 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiation by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) light quality control means to vary the irradiated light quantity of said light irradiating means and the exposure light quantity of said light image projecting means in accordance with a length of a stoppage time of said device so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said stoppage times.
Claim 11
Dependent Claim
33 words
The electrophotographic device according to claim 8, wherein said light quantity control means has timer means to count said stoppage time, and gradually varies said irradiated light quantity and said exposure light quantity.
Claim 12
Dependent Claim
38 words
The electrophotographic device according to claim 9, wherein said light quantity control means further includes a light adjusting circuit to electrically adjust said irradiated light quantity and said exposure light quantity by the output from said timer means.
Claim 13
Dependent Claim
44 words
The electrophotographic device according to claim 9 or 10, wherein said timer circuit also counts the operating time of the device, and adjusts said irradiated light quantity and said exposure light quantity in accordance with lapse of said operating time and said stoppage time.
Claim 14
Dependent Claim
22 words
The electrophotographic device according to claim 11, wherein said timer circuit is constructed with a charging and discharging circuit of a capacitor.
Claim 15
Dependent Claim
23 words
The electrophotographic device according to claim 12, wherein the time constant in said charging and discharging circuit differs in the charging and discharging.
Claim 16
Dependent Claim
29 words
The electrophotographic device according to claim 13, wherein said charging and discharging circuit is charged with lapse of the operating time and discharged with lapse of the stoppage time.
Claim 17
Dependent Claim
137 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiationn by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) light quantity control means to vary the irradiated light quantity of said light irradiating means and the exposure light quantity of said light image projecting means in accordance with a length of a previous operating time of said device so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said lengths of time.
Claim 18
Dependent Claim
137 words
An electrophotographic device, comprising: (a) light irradiating means to irradiate light on a photosensitive member having certain sensitivity characteristics; (b) charging means to uniformly charge said photosensitive member after the light irradiationn by said light irradiating means; (c) light image projecting means to project a light image after the charging by said charging means, thereby forming an electrostatic latent image corresponding to said light image on said photosensitive member; (d) developing means to develop said electrostatic latent image; and (e) light quantity control means to vary the irradiated light quantity of said light irradiating means and the exposure light quantity of said light image projecting means in accordance with a length of a previous operating time of said device so that the sensitivity characteristics of said photosensitive medium are compensated for variations in said lengths of time.
Claim 19
Dependent Claim
43 words
The electrophotographic device according to claim 15, wherein said light quantity adjusting means determines the initial values of said irradiated light quantity and said exposure light quantity based on said operating time and a stoppage time until said device commences its current operation.
Claim 20
Dependent Claim
35 words
The electrophotographic device according to claim 16, wherein said light quantity adjusting means further varies gradually said irradiated light quantity and said exposure light quantity with lapse of the current operating time of said device.
Claim 21
Dependent Claim
28 words
The electrophotographic device according to claim 17, wherein said light quantity adjusting means has time constant circuit means which counts both said stoppage time and said operating time.
Claim 22
Dependent Claim
38 words
The electrophotographic device according to claim 18, wherein said light quantity control means has a light adjusting circuit to electrically adjust said irradiated light quantity and said exposure light quantity by the output from said time constant means.
Claim 23
Dependent Claim
23 words
The electrophotographic device according to claim 19, wherein said time constant circuit is constructed with a charging and discharging circuit of a capacitor.
Claim 24
Dependent Claim
23 words
The electrophotographic device according to claim 20, wherein the time constant in said charging and discharging circuit differs in the charging and discharging.
Claim 25
Dependent Claim
29 words
The electrophotographic device according to claim 21, wherein said charging and discharging circuit is charged with lapse of a lighting time and discharged with lapse of a stoppage time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-28 | 1986-08-30 | 1987-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-28 | 1990-08-30 | 1991-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-28 | 1994-08-30 | 1995-03-01 | $7700.00 | Window Closed / Lapsed |